diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 99287a9ea..7653407a5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -40,7 +40,7 @@ jobs:
         with:
           python-version: "3.8"
       - name: Install tox
-        run: pip install tox~=3.0
+        run: pip install tox~=4.0
       - name: Run linting suite
         run: tox -e black
 
@@ -56,7 +56,7 @@ jobs:
         with:
           python-version: "3.8"
       - name: Install tox
-        run: pip install tox~=3.0
+        run: pip install tox~=4.0
       - name: Test with tox
         run: tox -e py38
         env:
@@ -76,7 +76,7 @@ jobs:
         with:
           python-version: "3.9"
       - name: Install tox
-        run: pip install tox~=3.0
+        run: pip install tox~=4.0
       - name: Test with tox
         run: tox -e py39-upstream-lm3-coverage
         env:
@@ -156,7 +156,7 @@ jobs:
         with:
           python-version: "3.8"
       - name: Install tox
-        run: pip install tox~=3.0
+        run: pip install tox~=4.0
       - name: Test with tox
         run: tox -e py38-lm3-coverage
         env:
diff --git a/environment.yml b/environment.yml
index 7af87d903..59bb1df89 100644
--- a/environment.yml
+++ b/environment.yml
@@ -58,6 +58,7 @@ dependencies:
     - statsmodels
     - tokenize-rt
     - tox
+#    - tox-conda  # Will be added when a tox@v4.0+ compatible plugin is released.
     - xdoctest
     - yamale
     - yamllint
diff --git a/pyproject.toml b/pyproject.toml
index 0ad4b938b..5d9f9cae8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -70,6 +70,7 @@ dev = [
   "pytest-xdist[psutil] >=3.2",
   "tokenize-rt",
   "tox",
+  # "tox-conda",  # Will be added when a tox@v4.0+ compatible plugin is released.
   "xdoctest",
   "yamale",
   "yamllint",